Device for inserting implants

ABSTRACT

A disposable device for inserting one or more implants, the device including a tublar cannula ( 10 ) having a tip ( 11 ), the cannula also serving as a container for the implants, a plunger ( 20 ) and a handle ( 30 ) having a first end ( 31 ) directed towards the cannula, and a second end ( 32 ) directed away from the cannula. The plunger and handle are attached or attachable to each other in fixed manner, and the cannula is arranged to be movable in the longitudinal direction, so that the plunger is placed within. The cannula can, after inserting the implant or implants, be drawn on top of the plunger ( 20 ) so far that tip ( 11 ) becomes covered by handle ( 30 ) or by a piece connected to handle ( 30 ), and/or cannula ( 10 ) is, when drawn to its extreme position, towards second end ( 32 ) of handle ( 30 ), arranged to be irretrievably locked in relation to plunger ( 20 ).

This application is a U.S. National Stage of International applicationPCT/FI01/00224, filed Mar. 7, 2001 and published on Sep. 20, 2001 in theEnglish Language.

The invention relates to a disposable device for inserting implants.

Syringes designed for inserting implants are described in patentliterature. For instance the patent publications EP 304700, EP 304107,WO 8806905, U.S. Pat. Nos. 4,451,254, 4,820,267 and GB 2199247 describevarious devices for inserting implants. The patent EP 304700 describes adevice where the sterility is improved by preventing the plunger fromaccidentally falling off the housing. The housing is made of plastic,but the cannula and the plunger are made of metal. The patent EP 304107introduces a disposable device for inserting implants, where the housingis made of plastic, but the cannula is made of metal. In particular saidpatent relates to a structure provided in connection with the plunger,whereby the implant is prevented from being pushed forward too early,i.e. when the skin is being penetrated. The published internationalapplication WO 8806905 relates to a complex device designed for repeateduse for inserting several successively positioned implants in thesyringe subcutaneously in a desired manner. In particular, thisinvention relates to an arrangement for inserting said implants. TheU.S. Pat. No. 4,451,254 likewise describes a device designed forrepeated use for inserting a plurality of implants, where the implantsare fed from an implant cartridge installed at the side of the syringe.The publication GB 2199247 describes a syringe for inserting hormonalimplants, which syringe is completely made of plastic, and meant forsingle use only.

The published international application WO 9510314 describes anall-plastic device for inserting implants; said device includes aseparate, protected incision blade, which after use can also beprotected by means of a structure provided in the device. Owing to thecooperating elements provided in the plunger and the implant housing,the plunger cannot be drawn out of the housing after the device has beenused, which effectively prevents any further usage of the device.However, the described device requires the use of both hands whileinserting.

The object of the invention is to provide a new disposable device forinserting implants, which device is safe to operate and to destroy afteruse, both in respect of hurting or infecting oneself.

Another object of the invention is to provide an advanced, disposabledevice for inserting implants, which device is effectively preventedfrom being reused.

Yet another object of the invention is to provide a device whereby oneor several implants can be inserted subcutaneously quickly and easily,by using only one hand in the operation.

Consequently, the object of the invention is a disposable device forinserting one or several implants, said device comprising

-   -   a tubular cannula provided with a tip, which cannula also serves        as a container for the implants,    -   a plunger, and    -   a handle with a first end directed to the cannula and a second        end directed away from the cannula,        wherein the plunger and the handle are attached or attachable to        each other in a fixed manner, and that the cannula is arranged        to be movable in the longitudinal direction, so that the plunger        is positioned inside the cannula.

The invention is characterized in that

-   i) the cannula can, after inserting the implant or implants, be    drawn on top of the plunger so far, that the tip of the cannula is    covered by the handle or a piece connected to the handle, and/or    that-   ii) the cannula is, when drawn to the extreme position towards the    second end of the handle, arranged to be irreversibly locked with    respect to the plunger.

The invention is described in more detail with reference to the appendeddrawings, where

FIG. 1 is a top-view illustration of a device according to theinvention, seen in full readiness for use,

FIG. 2 illustrates the device of FIG. 1, seen immediately afterinserting the implant/implants,

FIG. 3 illustrates the device of FIG. 1, seen in the end position afteruse,

FIG. 4 illustrates the device of FIG. 1 ready for use, seen in aside-view cross-section,

FIG. 5 illustrates the device of FIG. 4 in the end position after use,

FIG. 6 illustrates a detail of the locking mechanism shown in FIG. 5,

FIG. 7 illustrates an alternative locking mechanism, and

FIG. 8 illustrates the device of FIG. 1, provided with a protective cap.

FIG. 1 is a top-view illustration of a device according to the inventionin full readiness for use. The device includes a tubular cannula 10provided with a tip 11, said cannula also serving as a container forimplants. From the figure it is seen that the cannula contains animplant 50 ready to be inserted underneath the skin of an individual. Inprinciple, the cannula could also contain several successivelypositioned implants. The device further includes a plunger 20 and ahandle 30, provided with a first end marked with reference numeral 31,directed towards the cannula 10, and with a second end marked withreference numeral 32, directed away from the cannula. The plunger 20 andthe handle 30 are attached to each other in a fixed manner. From FIG. 1it can be seen that the plunger's end 21 directed towards the cannula isextended to outside the first end 31 of the handle, i.e. it is insertedto the cannula and supports the implant contained therein. The cannula10 is arranged to be movable in the longitudinal direction, surroundingthe plunger 20, so that when moving the cannula 10 towards the secondend 32 of the handle 30, the free end 21 of the plunger 20 makes contactwith the implant contained in the cannula. When the cannula is in thisposition, the device is ready for use.

From FIG. 2, which illustrates the device after inserting the implant,it is seen that the cannula 10 is in the longitudinal direction movablein the direction of the arrow, so that the plunger 20 remains inside thecannula. In the arrangements described in the drawings, the handle 30 isprovided with a channel 33 proceeding in the longitudinal direction ofthe plunger, in which channel the plunger 20 is fitted in a fixedmanner. The channel 33 allows for the longitudinal motion of the cannula10. In order to facilitate the moving of the cannula 10, that end 12 ofthe cannula that is directed away from the cannula tip 11 is providedwith a knob 40.

The device is used as follows: an incision is made in the patient's skinby means of the cannula's own tip 11 or by means of a separate blade.Thereafter the cannula, with the implants therein, is insertedunderneath the skin. By applying the arrangement illustrated in thedrawings, the device can be easily operated by one hand. The device isheld by the handle while penetrating the skin by the cannula. At theinsertion step of the implant, the cannula is drawn back, towards theholding hand, by gripping the knob 40 by the thumb of the same hand.

In FIG. 3, the cannula 10 is, after inserting the implant, drawn on topof the plunger 20, so far back (i.e. towards the handle end 32), thatthe cannula tip 11 remains completely in the protection of the handle30. Owing to this structure, the device is safer to handle after usethan the prior art insertion devices. The risk that the tip should cutwounds to the user and/or that possible blood drops left at the tipshould spread infections is eliminated by this arrangement.

In FIG. 5, where the device according to the invention is illustratedfrom the side, it is seen that when the cannula is drawn to its extremeposition towards the second handle end 32, the cannula is locked in thehandle 30 and therethrough also with respect to the plunger 20. Thelocking, which is seen in more detail in FIG. 6, is such that thecannula cannot be pushed further forward so that the tip 11 will comeout of the protection of the handle 30, without breaking the device.This structure further improves the operational safety of the device,because the sharp tip 11 remains irreversibly inside the handle. Saidstructure further ensures that the device cannot be reused.

The structure of the locking mechanism illustrated in FIG. 5 is shown inmore detail in FIG. 6. At the end 12 of the cannula 10, there isarranged a bracket 13 provided with a barbed hook 14. At the handle end32, there is formed a barbed hook 34 extending to inside the channel 33.When the cannula 10 is moved towards the handle end 32, the barbed hook14 slides over the barbed hook 34 owing to the flexibility of thebracket 13. Thereafter the elements 14 and 34 are locked to each other,so that it is impossible to move the cannula towards the tip.

FIG. 7 shows another arrangement, where at the end 22 of the plunger 20that is directed away from the cannula tip 11, there is arranged abarbed hook 23, which in cooperation with the barbed hook 14 causes thelocking.

When the device is ready for use according to FIG. 1, and the implantrests against the plunger end 21, it is recommendable that the positionof the cannula in relation to the plunger is locked in order to preventthe implant from being released prematurely. The described retrievablelocking can for example be a separate locking member, which can easilybe removed. See, for example, means 42 for reversibly locking thecannula, depicted in FIG. 4. As an alternative, the locking can be aspring-loaded press button or the like, which can easily be set on andoff by clicking. If the cannula contains several implants, it may besuitable that the spring-loaded locking system is automaticallyactivated after inserting each implant. In case the user wishes toinject the next implant beside the first one and not in successionthereto, he may turn the device somewhat without any risk of insertingthe second implant prematurely. When the device is in the correctposition, the user releases the locking system and inserts the implantby pulling the cannula towards the hand.

The motion of the cannula can also be guided by means of marks, forinstance lines, made in the handle and/or in the cannula. In case thedevice is meant for a plurality of implants, the handle and/or thecannula is suitably provided with one mark per each implant.

The cannula 10 of the device is suitably protected by a separateprotecting cap 60 (FIG. 8). The protecting cap is detached before usingthe device.

The device that is ready for use and suitably packed in a protectivepackage, complete with the implants contained therein, is sterilized forexample by irradiation or by gas. In case the sterilization is carriedout by gas, it is recommendable that the cannula 10 and the possibleprotecting cap 60 are provided with apertures 70 that permeate thesterilizing gases (FIGS. 1 and 8).

The cannula of the device can be made of any suitable material.According to one alternative, the cannula 10 and the tip 11 thereoftogether constitute a uniform piece made of metal. As an alternative,the tubular part of the cannula 10 is made of plastic wherein a metallictip 11 is attached. According to another alternative, the cannulacomplete with the tip constitutes one single piece made of plastic. Inthis case, there is probably needed a separate instrument for breakingthe skin of the patient. Consequently, an incision blade can beconnected to the protecting cap 60 or handle 30 of the device in a waydescribed in the patent publication WO 95/10314. In that case in thevicinity of the incision blade, there is arranged a protective bracketfor protecting the blade. Said bracket can be provided with a slot inwhich the used blade can be inserted according to FIGS. 6-8 of saidpatent publication.

In the above described arrangements, the handle is an object providedwith an open channel. As an alternative, the handle could be a tubularobject wherein the plunger is fitted, in which case in between theplunger and the inner surface of the tubular object, there is left roomfor the motion of the cannula. In the wall of the tubular object, thereis arranged a longitudinal slot for the motion of a knob extending tooutside the tube wall and attached to the cannula. This principle isintroduced for instance in the U.S. Pat. No. 4,820,267, in FIG. 2.However, a handle provided with an open channel may be recommendable,because the structure is simpler, and the device is easier to operatewith one hand.

The above-mentioned embodiments of the invention are only examples ofhow the idea according to the invention can be realized. For a manskilled in the art, it is obvious that the various embodiments of theinvention can be modified within the scope of the appended claims.

1. A disposable device for inserting one or several implants, saiddevice comprising a tubular cannula provided with a tip, said cannulaalso serving as a container for the implants, a plunger and a handlehaving a first end directed towards the cannula, and second end directedaway from the cannula, wherein said plunger and handle are attached orattachable to each other in fixed manner, and said cannula is arrangedto be movable in the longitudinal direction, so that the plunger isplaced inside the cannula, and wherein i) the cannula can, afterinserting the implant or implants, be drawn on top of the plunger sofar, that the tip of the cannula becomes covered by the handle or by apiece connected to the handle, and ii) the cannula is, when drawn to itsextreme position towards the second end of the handle, arranged to beirretrievably locked with respect to the plunger, and wherein the handleis provided with a channel proceeding in the longitudinal directionthereof, which channel allows the cannula to move in the longitudinaldirection, and that the end directed away from the tip of the cannula isprovided with a knob, further comprising means for reversably lockingthe cannula when an implant rests against an end of said plunger.
 2. Thedevice of claim 1, wherein the device is provided with a protecting capfor protecting the cannula.
 3. The device of claim 1, wherein thecannula and optionally a protecting cap are provided with aperturespermeable to sterilizing gases.
 4. The device of claim 1, wherein thetip of the cannula is made of metal, and optionally the cannula itselfis also made of metal.
 5. A disposable device for inserting one orseveral implants, said device comprising a tubular cannula provided witha tip, said cannula also serving as a container for the implants, aplunger and a handle having a first end directed towards the cannula,and a second end directed away from the cannula, a means for reversablylocking the cannula when an implant rests against an end of said plungerwherein said plunger and handle are attached or attachable to each otherin fixed manner, and said cannula is arranged to be moveable in thelongitudinal direction, so that the plunger is placed inside thecannula, and wherein the cannula is, when drawn to its extreme positiontowards the second end of the handle, arranged to be irretrievablylocked with respect to the plunger, wherein the handle is provided witha channel proceeding in the longitudinal direction thereof, whichchannel allows the cannula to move in the longitudinal direction, andthat the end directed away from the tip of the cannula is provided witha knob.